Does anyone know why dhclient would be giving me an IPv6 address. It shouldn't be any settings on my router because none of my other machines have this problem. My router also shows it having a normal IPv4 address. The computer can't ping any of the other machines on the network or any internet addresses.

IPv6 doesn't interoperate with DHCP, it doesn't need it. IPv6 comes with its own address discovery mechanisms, which is partly what you are seeing.

Any OS supporting IPv6 generates a link-local IPv6 address that is derived in part from the mac address. It doesn't mean anything and will not interfere with IPv4 operations in any way.

If you are configured for DHCP and are getting an IPv4 address then your DHCP is working. Thats not to say that what DHCP is handing out is correct, that depends on how you've configured it

Pete